Extrudates are commonly used to produce materials used in automotive applications, such as, for example, in weatherseals or the like. Such weatherseals are primarily used to provide seals against wind, rain, noise and the like, in situations wherein glass and metal (or other materials) are in contact with each other (in fixed or movable situations), or in situations where metal components (or other materials) are in a movable relationship to one another, such as, for example, a door, trunk or hood opening with respect to the frame or body of the automobile.
The term “extrudate” is used since these materials are typically manufactured by extruding a selected, extrudable material through an extruder to form a continuous length of the selected material. The extruded material may then be, if necessary, cut to length, and/or bent or shaped to form the desired “extrudate” material.
By “extrudable” is meant that a material blend can be processed in an available, commercial extruder or injection moulding machine which provides internal mixing at a temperature in the range from, for example, about 180° C. to 240° C. with a residence time less than 5 min, preferably in the range from 30 sec to 2 min.
Extrudates in the automotive industry, and in particular weatherseals, are typically produced as a long, hollow ribbon of flexible material. The flexible material is chosen to enable the material to be fitted to the body of the automobile. The extrudate is commonly hollow to allow for increased flexibility, and reduce weight and costs by minimizing the amount of material used. As such, there are commonly one or more passages, or passageways, which are at least partially, and commonly, totally enclosed within the extrudate. While these passageways reduce the amount of material used, decrease weight, and allow for increased flexibility of the extrudate, it can be desirable under certain circumstances to strengthen or otherwise stiffen the extrudate material. In prior art applications, this task would commonly be achieved by inserting a pre-formed plug or “stuffer”, typically made of a foamed material, into a passageway at one end of the weatherseal, and using compressed air to push or otherwise move the plug or stuffer to a desired location within an extrudate passageway.
Alternatively, the plug or stuffer might be formed in the weatherseal by insertion of a foaming material from a nozzle inserted into the passageway through one or more ends of the weatherseal, and allowing the foaming material to form a plug, in situ. While these operations provide the necessary stiffening of the weatherseal, insertion of the plug in the correct location can be difficult, and commonly involves the use of manual labour. Further, it should be noted that these operations are commonly conducted off of the production line since they are not easily automated. The costs of such “off-line” operations can be high, and as such, it would therefore be desirable to provide an alternative method for the placement of stuffers or plugs within the hollow shell and/or passageways formed within the shell of the extrudate. It would also be advantageous to provide an alternative method which could be automated and which would be suitable for “on-line” processes.